package com.iteima.reggie.controller;

import com.iteima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;
    /**
     * 文件上传
     * 参数MultipartFile file中参数名必须为file,否则为空,与前端一致
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) {
        //file是一个临时文件,需要转存到指定位置,否则本次请求完成后临时文件会删除
        log.info(file.toString());//abc.jsp
        //以原始文件名命名(不推荐)
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));//文件名后缀 .jsp

        //创建 一个目录
        File dir = new File(basePath);
        //判断该目录是否存在
        if (!dir.exists()){
            dir.mkdirs();
        }

        //使用UUID重新生成文件名称,防止文件名称重复造成文件覆盖
        String fileName = UUID.randomUUID().toString()+suffix;//dsadasad + .jsp


        try {
            file.transferTo(new File(basePath+fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        try {
            //输入流,通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));
            //输出流,通过输出流将文件写回浏览器,在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new  byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();//刷新
            }

            outputStream.close();
            fileInputStream.close();

        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}
